The right to boycott has a long history in the United States, from the American Revolution to Martin Luther King Jr.’s Montgomery bus boycott to the campaign for divestment from businesses serving apartheid South Africa. Nowadays we celebrate those efforts. But precisely because boycotts are such a powerful form of expression, governments have long sought to interfere with them — from King George III to the police in Alabama, and now to the U.S. Congress.

The Israel Anti-Boycott Act, legislation introduced in the Senate by Benjamin L. Cardin (D-Md.) and in the House by Peter J. Roskam (R-Ill.), would make it a crime to support or even furnish information about a boycott directed at Israel or its businesses called by the United Nations, the European Union or any other “international governmental organization.” Violations would be punishable by civil and criminal penalties of up to $1 million and 20 years in prison. The American Civil Liberties Union, where we both work, takes no position for or against campaigns to boycott Israel or any other foreign country. But since our organization’s founding in 1920, the ACLU has defended the right to collective action. This bill threatens that right.

The Israel Anti-Boycott Act is designed to stifle efforts to protest Israel’s settlement policies by boycotting businesses in Israel and the occupied Palestinian territories. The bill’s particular target is the boycott, divestment and sanctions (BDS) movement, a global campaign that seeks to apply economic and political pressure on Israel to comply with international law.